Presently available X-ray machines are commonly provided with a collimator having a continuously adjustable shutter system, which may be controlled by a technician for selectively varying the cross-sectional size of a projected X-ray beam. A practical drawback of equipment of this type is the failure of all technicians to take the time required to properly adjust the shutter system, so as to reduce beam size to that required for a given procedure and thereby minimize exposure of a subject being X-rayed to radiation.
Heretofore, various proposals have been made to fit X-ray machines with shield devices for purposes of selectively limiting the size of a projected beam size, without need for changing the adjustment or setting of the shutter system of a collimator from a most often used or preset large beam size, such as that size required for a chest X-ray procedure. One example of a shield device of this general type is that disclosed in U.S. Pat. No. 3,849,649.